Value of Sonography in Determining the Nature of Thyroid Nodules: Evaluation of the Sonographic Characteristics

The purpose of this study was to evaluate all the sonographic characteristics in determining the nature of thyroid nodules. High-frequency sonograms of the thyroid were performed in 134 patients who were referred by three endocrinologists because of abnormal results on a thyroid physical examination. Sensitivity, specificity, positive and negative predictive value, and accuracy for individual sonographic characteristics were determined by comparing the results of the sonographic examination and fine needle aspiration biopsy (FNAB). Of 95 patients, 81 had benign FNAB reports that included nodular goiter, Hashimoto thyroiditis, and acute thyroiditis. Fourteen patients had cells that were malignant or suspicious of malignancy. The most accurate diameter for differentiating malignant from benign nodules was 3.9 cm. Considering the high level of negative predictive value of all the sonographic criteria, it is better to observe the patients rather than to apply FNAB when there is no suspicious finding of malignancy in the sonographic examination of a nodule.